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Feb. I9, 1929. 1,702,473

G. W. HEISE ET AL DRY CELL Filed Dec. l2, 1923 um' FZ7 WMM Patented Feb. 19, 1929.

UNTED STAES es'irin't oFFlCE.

GEORGE W. HEISE, OF BAYSIDE, AND ERVIN A, SCHUMCHER, F BROOKLYN, NEW YORK, ASSGNORS TO NATONAL CARBON COMEANY. INC., A CORPORATION OF NEW YORK.

DRY CELL.

Application ned Detemoer 155, 1923.

rlhe invention is a dry cell of: in'rin'oved construction. rlhe object ot the invention is to provide a larger anode suril'ace than has heretofore been present in cells o t similar si?. and kind7 thereliy extending' the usotful lite o'i' the cell; and to do this without sacrilicing any ot the desirable 'tentures ot' prior conslriu'tions.

Dry cells' ot' the larger sizes. used in stationarv installations. are now made hy lininga zine eup with bihulous material, centering a (fr l non rod in the lined cup. and then packingt the space between the rod andthe cup with depolarizing mixture wet with electrolyte. In such a cell the sides and bottom oit the cup are subjected to aboutl the same de lg're i ot' electroly'tie action during service7 and the bottom may become perforated soon as or even hetore the sides. This is notV seriously ohjeetionahle as the bottom like the sides serves only as anode and container Ytor the other parts ot 'the cell.

The above method is not well adapted to the nmnntacture ot small cells', such as those intended i'or use with flashlights. ln making' this type ot' cell, the carbon rod and depolarizing mix making up the oathr'ide are Ytermed into a self-sustaining' cylinder or bohhin7 which is inserted axially `into the zinc eup. There must he enough dill`erence between the diai'neters ot the bohbin and cup to permit the hohbin to he readily inserted.

lllhile small dry cells ot' this latter type are heilig' assembled, the hobliin is simported from below7 and it remans in coru'iact with its support when the cell is tinished. fit will be :1pparent that it the space under the hobhin is titled with electrolyte, like the annular space at. the sides of the holibin. the comparative rates et corrosion ot the eupbottom and the cup-sides -will depend upon their distances from the bohbin or cathode, proximity of course promoting' corrosion.

In flashlight cells the cupwhottoin serves not only as anode anu container, hut also as a conta :t member against. which the cathode of another cell or terminal ot' the 'tlashligi'ht casing' hears. Qt is therefore desirable that the hot-- tom remain impertorate until the cell oxhausted. The bottom ot the cup is usual' closer to the cathode than the sides are. and in suoli case the most rapid corrosion will oeour at the bott-om of the cell unless special measures are adopted to prevent this. The measure usually employed is to place a disc Serial No. SSiltz.

ot insulating' material, 'lor example paraffininipregnated paper-board. on the bottom of the cup. and to set the hohbin on this while the cell is being assemhlcd.

ln nccordance with our inventionrno .in-' sulatingir disc is used. it necesa ry to prevent contact between the bobbin and cup-bottom. a disc ot biliulous material is placed hetween them. Such disc is rendered Conductive by saturai ion `with electrolyte. and ot' course permits eleetrolytic action to go on over all the upper surface ot the eup-boitmn.

The omission ot the insulating' disc will often result in the cup-bottoni beioming' the region where the anode is most strongly attacked elertrolytically. To prevent premature perforation ot the cup-bottom. we reinforce it. either by making` it thicker than the ,side walls or by liningr it wit-h a. separate zine disc otl s iitable thickness. The latter method is preterred, as it has manufacturing advantages.

.lu the accompanying drawing we show in Fie'. 1 a cell of our improved construction with the eup-liiottom reinforced by `increasingv its thickness. Fie'. 2 a modification having' the zine` disc reinforcement. Except for Y the parts indicated by legends on the drawing, both cells are o't` usual construction. They comprise the usual dimolarizing; hobbin set in electrolyte paste, and since these features are no part ot' our invention they are somewhat diagrannnatieally shown and are not Jfurther described.

lliv cells made as described herein are capable ol l iving' in ceri ain classes ot' service an iniln'ovennu ot as much as 9.0% over cells of the, present standard constructimi.

Vie claim:

l. in a dry cell. a soit-sustaining cathode, and a '/.ine cup anode havinga bottom reinforced with a zinc dise. said dise beingeX- posed to electrolytic action.

2. ln a dry cell. a self sustaining Cathode and a zine cup anode having' a bottom reinforced with a zinc disk. the thickness of said disk being' at least equal to that of the walls ott the cup, said disk heine; exposed to electrolytie action.

In testimony whereof, I aiiix my signature.

GEORGE Vf. HEISE.

In testimony whereof, I atiix my signature.

ERVIN A. SCHUMACHER. 

